Film presser pad assembly



June 24, 1941.

KqBRENKERT FILM PRESSER PAD ASSEMBLY Original Filed Jan. 21, 1939 2Sheets-Sheet l mm M V m W June 24, -1941. K. B'RENKERT FILM PRESSERPAD'ASSEMBLY 2 Sheets-Sheet 2 Original Filed Jan. 21, 1939 INVENTOR.

Patented June 24, 1941 FILM PRESSER PAD ASSEMBLY Karl Brenkert,

Detroit, Mich.,

assignor to Brenkert Light Projection Company, Detroit, Mich., acorporation of Michigan Original application January 21, 1939, SerialNo. 252,149. Divided and this application May 24, 1939, Serial No.275,425

6 Claims. (CL 8817) This application is a division of my co-pendingapplication Serial No. 252,149 filed January 21, 1939, which hasresulted in Patent No. 2,204,884 of June 18, 1940.

The invention pertains to the pads or shoes carried by the film gate forresiliently engaging the rear surface of the film as it travels alongthe aperture plate.

The pads are provided in pairs above and below the projection apertureas well as at the aperture, to hold the film fiat before reaching andafter leaving aperture, to ensure the desired fiat condition at theaperture. Although the pads cover a substantial length of film, a thicksplice in the film will not disturb the frame at the aperture untilengaging the pads at opposite sides of the aperture, since the latterare separate from the pads above and below the aperture.

The pads are backed by springs, and it is the object of the invention toprovide a means for simultaneously adjusting the tension of the severalsprings by a simple manipulation. Within the scope of the invention, thepads need not be located with respect to the projection aperture in themanner described.

More specifically, the separate pads are engaged by leaf springsanchored to a common rod journaled in the body. The angular position ofthe rod determines the tension of the springs. The position of the rod,and hence the tension of the springs, is regulated by a means of a setscrew bearing against an arm or lever extending from the rod.

The invention is fully disclosed by way of example in the followingdescription and in the accompanying drawings in which:

Figure 1 is a side elevation of the gate assembly;

Figure 2 is a section on the line 2-2 of Figure 1;

Figure 3 is a vertical section on the line 3-3 of Figure 2;

Figure 4 is a detail end view of the lens tube;

Figure 5 is a section on the line 55 of Figure 1, and

Figure 6 is a section on the line 66 of Figure 1.

Reference to these views will now be made by use of like characterswhich are employed to designate corresponding parts throughout.

In Figures 5 and 6 is shown one of the end walls I of a projectorhousing having a length wise Vertical wall or partition 2 constitutingthe inner side wall of the film compartment and ordinarily dividing theinterior of the housing lv into a film compartment and a mechanismcompartment. The outer side wall of the film compartment is constituted,at least in part, by a door section 3 hinged at 4 to the end wall I.

To the partition 2 is secured a bracket 5 formed as shown more clearlyin Figure 5. The base is secured to the carriage by a screw [4 threadedinto the carriage.

To the partition 2 is secured an aperture plate IS in edgewise mannerand perpendicular thereto in more or less the usual fashion. The gatebase I carries a gate body l1 standing vertically and parallel to theaperture plate to cooperate in holding the film against the latter. Thebody I! is a box-like structure having a detachable face wall [8 toenable assembly of other parts therein.

In the plate 18 are mounted a number of alined pads, each consisting ofa pair of vertically disposed and horizontally spaced U-shaped membersl9 having their legs 20 slidably mounted in the plate and theirintermediate or main portions disposed outside the plate, as illustratedin Figure 3. The ends of each such pair, inside the base member, arejoined vertically and horizontally by thin metal strips 2| suitablyfastened to the ends, by means of screws 22.

A vertical rod 23 is rotatably mounted in the body I"! near one of itsside walls and extends from top to bottom. Leaf springs 24 are wrappedaround the rod, with one end anchored thereto and the other end engaginga horizontal strip 2! to exert an outward pressure on the pads. A fixedarm 25 extends from the rod 23 into the body l1. and has its 'free endengaged by a set screw 26 threaded in the back of the body, Whereby thetension of the springs 24 against the pads may be adjusted.

The pads above and below the aperture are separate from these at thesides of the aperture. Thus, althoughthe'film is engaged by pads over asubstantial length, a splice engaging any pair of pads will not affectthe film over this entire length, but only at those pads engaged by theplice.

The aperture plate It has the usual film aperture 21 with verticalmarginal guides 28 between which the film is adapted to run. Runways 29are. extended from the guides into the aperture and are engageable bythe margins of the film when the latter is inserted between the guides.The U-shaped members of the film pads are so positioned laterally as tohold the film against the runways 29 by the adjusted tension of thesprings 24, as shown in Figure 2.

A fulcrum block 33 is fixedly mounted with relation to the gate base IIand may consist of an extension of the boss 6 which is an integral partof the bracket 5. A long screw 3| threaded into the fulcrum block hasrotatably mounted thereon a toggle operating lever 33. A link 34 extendsrigidly from the hub approximately half way to one of the bosses ID ofthe carriage 3. A link 35 joins the last named boss to the free end ofthe link 34 and is pivotally attached to both parts to complete thetoggle which is operated by the lever 33.

Figure 1 illustrates the locked position of the gate against theaperture plate in one of the extreme positions of the toggle. Theintermediate knuckle 36 of the toggle is below the line of centers ofthe end knuckles and the inner end of the link 35 extends into and bearsagainst the bottom of a slot 3'! in the link 34. Thus, the gate cannotback away from the aperture plate, unless the lever 33 is actuated, andconsequently no springs are needed to hold the gate in its operativeposition. This construction obviously simplifies the device and reducesthe cost and also eliminates the undesirable slamming of the gateagainst the film and aperture plate resulting from the use of gatesprings.

The base II and body I! of the gate are readily removed from thecarriage 9 and from the projector housing, when desired, by releasingthe screws l and 3i. The carriage 9 and bracket 5 may be removed byreleasing the screws 38 which fasten the latter to the partition 2.

The inner surface of the door 3 carries a stop 39 which lies over thefree end of the toggle operating lever 33 when the latter is in thelocking position shown in Figures 1 and 5. The stop is constructed tostrike against the lever when the latter is in release position, so thatthe door cannot be closed unless the gate is closed.

The back wall of the gate body I! is formed with a flanged opening 43 toreceive a split light tube 4! having one end grooved at 42 to receivethe flange when inserted in the opening. At op-' posite sides of itssplit 43, the tube has finger pieces 44 by which it may be grasped tocompress the tube for insertion or removal. The tube 4| is receivedtelescopically in a light and lens tube 45 carried by the housing, sothat the light beam is fully enclosed regardless of the movements of thegate.

At the lower end of the gate is a device for holding the film firmlyagainst an adjacent roller or sprocket 46 (Figure 1). This deviceincludes a back plate 41 at the ends of which are pairs of thin metalshoes 48. The back plate is supported by a screw 49 passed looselytherethrough and threaded into a lip 56 extending angularly andrearwardly from the lower end of the plate I8. The shoes of each pairengage the film at both sides of the roWs of perforations therein forthe sprocket teeth. The shoes are maintained in their proper spacing byspacer rods 5| passed through their ends, as shown in Figure 3.

The free end of the screw 49 carries a hollow nut 52 in which is seateda spring 53 bearing against the member 4?. Through the spring, the shoes48 hold the film under pressure against the member 46. The shoes arealso capable of a universal movement, in response to Variations in thethickness of the film, by reason of the loose mounting of the screw 49in the plate 41.

The pressure of the spring is adjusted by turning the nut 52 on itsthreads.

Although a specific embodiment of the invention has been illustrated anddescribed, it will be understood that various alterations in the detailsof construction may be made without departing from the scope of theinvention, as indicated by the appended claims.

What I claim is:

1. A film gate comprising a body, a vertical series of pads slidablymounted therein, a vertical rod journaled in said body, horizontalsprings anchored directly to said rod and engaging said pads, and meansfor adjusting the angular position of said rod against the tension ofsaid springs, whereby to adjust said tension.

2. A film gate comprising a body, a vertical series of pads slidablymounted therein, a vertical rod j ournaled in said body, horizontalsprings anchored directly to said rod and engaging said pads, an armextending from said rod, a set screw threaded in said body andengageable with said arm to turn the same and said rod against thetension of said springs, whereby to adjust said tension.

' 3. A film gate comprising a body, laterally spaced U-shaped membersdisposed vertically substantially outside of said body and having theirlegs extending through a wall of said body, strips joining the ends ofsaid legs, a vertical rod journaled in said body, horizontal springsanchored directly to said rod and engaging certion of said strips, andmeans for adjusting the angular position of said rod against the tensionof said springs, whereby to adjust said tension.

4. A film gate comprising a body, pairs of laterally spaced U-shapedmembers disposed vertically substantially outside of said body andhaving their legs extending through a wall of said body, strips joiningthe ends of the legs of each pair, a vertical rod journaled in saidbody, horizontal springs anchored directly to said rod and engagingcertain of said strips, and means for adjusting the angular position ofsaid rod against the tension of said springs, whereby to adjust saidtension.

5. A film gate comprising a body, pairs of laterally spaced U-shapedmembers disposed vertitically substantially outside of said body andhaving their legs extending through a wall of said body, strips joiningthe ends of the legs of each pair, a vertical rod journaled in saidbody, horizontal springs anchored directly to said rod and engagingcertain of said strips, an arm extending from said rod, a set screwthreaded in said body and engageable with said arm to turn the same andsaid rod against the tension of said springs. whereby to adjust saidtension.

6. A film gate comprising a body, pairs of laterally spaced U-shapedmembers disposed substantially outside of said body and having theirlegs extending through a wall of said body, strips joining the ends ofthe legs of each pair, a rod journaled in said body, springs anchored tosaid rod and engaging certain of said strips, one of said pairs beingdisposed at the sides of the projection aperture in the gate, and theother pairs being disposed above and below the first named pair, andmeans for adjusting the angular position of said rod against the tensionof said springs whereby to adjust said tension.

KARL BRENKERT,

